1. Chordates Part 3

2. Fins are thin membranes supported by bone

3. Secrete mucus, reduce drag, slimy Swim bladder to adjust buoyancy to compensate for heavy bone.

4. Can breath while stationary Largest group of living vertebrates Ichthyology: study of fish

5. Tetrapods (four footed): land vertebrates Evolved lungs- air breathing

6. Amphibians: (class Amphibia) Evolved from lobe-finned fish and lung fish 350 mya First vertebrates on land Must reproduce in water Amphibian means two lives, in water as larval stage and on land as an adult Not marine…. Why?

11. Reptiles: (class Reptilia) 300 million years old Snakes, turtles, saltwater crocodiles, and marine iguanas

13. Skin covered with scales, water tight

14. Internal fertilization Egg has leathery waterproof shell to reproduce on land

15. Ectotherms - live in warmer climates

16. Ichthyosaur (extinct)- reptiles that returned to the ocean

17. Sea Turtles: Shell fused to backbone

18. Can not retract head like land based tortoises and turtles

19. Legs modified into flippers Leave water only to lay eggs Examples: Green, Hawksbill, Loggerhead, Kemp’s Ridley and the Leatherback (largest) Migrate long distances, using wave motion and magnetic field

20. Birds: (class Aves) Evolved from a reptilian ancestor

21. Reptilian remnants include: shelled egg and scales on legs Archaeopteryx 150 million year old reptile with feathers, teeth and tail with vertebrate Sea birds have evolved body shape and structure to swim, fly or feed in the ocean